Data Reduction on Ellipsoid

What is the deflection of the vertical in geodesy?

• The deviation of a surveyor’s instrument from true north
  

• The angular difference between the vertical line and the ellipsoid normal

• The shift in latitude due to tectonic movements

• The effect of atmospheric refraction on geodetic angles

Which factors contribute to the deflection of the vertical?

• Variations in Earth's gravity field

• Earth's magnetic field

• Atmospheric pressure changes

• • Satellite orbits

Deflection of the vertical is typically divided into which two components?

• Meridian and parallel components

• Horizontal and vertical components

• Astronomical and geodetic components

• Large-scale and small-scale components

The meridional component of the deflection of the vertical affects which coordinate?

• Longitude

• Latitude

• Height

• Time

Which of the following equations represents the relationship between geodetic latitude (ϕG​) and astronomical latitude (ϕA​)?

• ϕG​=ϕA​−ξ

• ϕG​=ϕA​+ξ

• ϕG​=ϕA​×ξ

• ϕG​=ϕA​/ξ

How does deflection of the vertical impact geodetic surveys?

• It causes systematic errors in distance measurements

• It affects the conversion between astronomical and geodetic coordinates

• It makes angles appear smaller than they are

• It only affects surveys conducted at sea

Which of the following best describes the relationship between the geoid and the ellipsoid?

• The geoid is always above the ellipsoid

• The ellipsoid is a theoretical smooth surface, while the geoid is an irregular equipotential surface

• The geoid is unrelated to the ellipsoid

• The ellipsoid is used for GPS, but the geoid is only used for nautical navigation

What is the purpose of reducing geodetic measurements before performing coordinate calculations?

• To adjust data for consistency with the reference ellipsoid

• To make survey data appear more accurate

• To eliminate all errors from the dataset

• To simplify computations without affecting accuracy

How does deflection of the vertical influence local surveying operations?

• It changes the shape of the ellipsoid

• It alters geodetic control point positions

• It affects the orientation of a total station

• It modifies GNSS satellite orbits

Which reference surface is used to define the deflection of the vertical?

• The celestial sphere

• The magnetic field

• The ecliptic plane

• The geoid